Electric-motor governor



ll'g. 5 1924. l

I H W. CRANE 1,503,818

ELECTRIC Moron GOVERNOR Filed April 14 1922 7 w .5, A W f E! l" III u Patented Aug., 5, 1924.

naires stares raient orties.

isaaaia HERBERT W. CRANE, OF CHICAGO, ILLINOIS.

ELECTRIC-MOTOR GOVERNOR.

Application led April 14, 1922. Serial No. 552,722.

vparticularly to' a specific application of a well Aknown governing principle to an electric motor. Y

One of the particular objects of my invention is to providea simple device which may be applied to and operate efficiently in connection with a variable speed 'electric motor with the object of maintaining a constant speed thereof under different working conditions. The device utilizes the common tendency of the motor armature to reciprocate longitudinally to a very limitedv extent, this reciprocation being stiflicient to move Icooperating' disks into and out of frictionalpengagement. The required movement is secured by mounting two or more governing arms on the shaft exteriorly of the motor, the arms acting through thrust pins carried by aV friction disk to bring pairs of friction surfaces successively into contact.

The invention will be more readily understood by reference to the accompanying drawings, wherein,

Fig. 1 is a longitudinal sectional view showing a governor of my invention applied to a motor casing, and

Fig. 2 is an end view thereof.

In the drawings it will be seen that the governing device is intended to be associated with a motor having a casing 10, provided with an end wall 11, and with an armature shaft 12. The governing action is secured in part by the cooperation of two 'friction disks 13, 14, the former rigidly fixed to the end wall 11, of the casing and the latter secured to the shaft 12 by means of a pin 15. On the overhung end of the shaft 12 is secured a sleeve 16, by means of a key 12a, and a threaded adjusting nut 12b held in adjusted position by a set screw or bolt 12C. Bell cranks which actas governor arms are pivoted to the sleeve by means of shafts 17 mounted in apertured ears 18. One arm 19 of the bell crank carries an adjustable weight 20, and the other arm 21 engages a thrust pin 22, which projects through the flange of the sleeve and is fixed in a metallic disk 23. The

disk is in close proximity to a fibre block 24, secured to the end wall 11 of the motor. "A

'tension spring 25 connects the arms 19 to the bell cranks and tends to neutralize the centrifugal force, tending to separate the gov,- ernor weights 20. The action is as follows:

When the parts are installed the armature shaft is permitted to have such slight freedom Vof longitudinal movement as will permit the friction disks 13, 14, 23, 24, to

separate. The separation need be very slight; of course, any separation even though vit be only 1/100th of an inch is sufficient.

When the armature starts its rotation the governor weights are urged voutwardly by the centrifugal force and the disk 23 is caused to contact the block 24. The exertion of additional force by the governor will cause the armature shaft to move to the right as viewed in Fig. 1, this movement being sufficient to cause the friction disks 13, 14, to contact. Thus the speed of the motor may be controlled within narrow limits, all without change in the design of the motor and without the utilization of expensive or complicated parts. The device is particularly applicable for use on motors intended for intermittent operation. The provision of the two opposed friction-producing areas enables accurate control of speed without thrust on any motor bearings.

Obviously the construction is capable of some modification and I do not wish to be limited except as indicated in the appended claims. i

I claim:

1. In a governing device for electric motors, the combination of an armature shaft mounted for limited longitudinal reciprocation.` a casing, a friction disk rigid with said shaft and adapted to cooperate with a wall of said casing, and governor weights attached to and operated by said shaft whereby to effect such movement of the shaft as will cause the friction disk to move into contact with the casing.

2. In a governing device for electric motors, the combination of a housing having an end wall, an armature shaft mounted in said housing, a friction disk secured to the shaft and in close proximity to the end wall of the housing, governor arms and weights attached to and operated by the rotation of the shaft, and means operable by the governor arms for effecting longitudinal movement of the Shaft whereby to -With the end wall ofthe housing.

bring said friction disk into Contact with an adjacent Wall surface.

3. In a governor for electric motors, the combination of a housing having an end Wall, an armature shaft mountedT inV the housing, a disk rigidly secured to the shaf* at a point interiorly of the housingk andl in proximity to said end Wall, governor arms secured to the shaft and' adapted to-bemoved by centrifugal force, fand means vproviding, a Xed thrust.A surface against Which-,1 theV eX- pansive force of said arms mayk be exerted, vvhereby to effect longitudinal movement of theY shaft and to bring said disk into Contact L@In a governor for electricfmotors, the

i combination of ahousing, anarmature-shaft mounted therein, a friction disk securedto the shaft andz locate di interiorlyY-of, the housing` in.. close proximity toA the end Wall thereof; governor-A arms 'securedf tomr` an overf hung-end of-f said; shaft, means-*provided by said casing serving asan abutment-against Which the centrifugal 1 force of-thearms may be eierted, whereby theV centrifugal force tends to effect bodily longitudinal movement ofc-the shaft4v and governor arms totheeX- the armature shaft, the governing deviceV and the ,frictionY disk into Contact With said Wall; Y Y z Y Y 6,1 In a governor for electric motors,\theY coniibinationof-an armature shaft', a casing'.

means providing f pairs of friction surfaces on theinterior-and" exterior respectively, of Y.

Van end- Wall oftheV casing, friction Vdisks rotatable with said shaft,foneof the` disks being-movable longitudinally of theshaft,Y

and' the other fixedff relative thereto, andla;

governor actingtofmove said' longitudinally movable-` disk into contact withl ay' friction said fixed"disk.-into,Contact.V i Y SignedY at Chicago,"l Illinois, Ythis o'tfAprn, 192.2.

'surface and` then tomovezsaidfshaft to bring 28th..,dayf HERBERTW. CRANE: 

